SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab7618a142ee8542f340ddfaa9b795c3939cc86a71e5d13bcd60ff726c055f5f' 
  AND token = 'shljE8etog4NVjXYjFVTvRzkbcO0GF9ytZvMbkbN37s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}